Conventional communication systems transmit data signals at a given rate from a data transmitter to a data receiver over a communication media such as optical fiber, cable or twisted pair. Higher data transmission rates that enable enhanced telecommunications services may give rise to inter-symbol interference (ISI) when the frequency response of the communication media is non-flat over the bandwidth of the transmitted signal.
For example, in optical communication systems chromatic dispersion and polarization mode dispersion which result from variation of light propagation speed as a function of wavelength and propagation axes may create high levels of ISI at high data rates or for long channel lengths. These bandwidth limitations of typical fiber optical cable tend to spread transmitted pulses. If the width of the spread pulse exceeds a symbol duration, overlap with neighboring pulses may occur, which may limit the achievable bit error rate of the communication system.